Classifications

• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D11/00—Control of flow ratio
  • G05D11/006—Control of flow ratio involving a first fluid acting on the feeding of a second fluid
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0324—With control of flow by a condition or characteristic of a fluid
  • Y10T137/0329—Mixing of plural fluids of diverse characteristics or conditions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0324—With control of flow by a condition or characteristic of a fluid
  • Y10T137/0363—For producing proportionate flow
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/2496—Self-proportioning or correlating systems
  • Y10T137/2499—Mixture condition maintaining or sensing
  • Y10T137/2506—By viscosity or consistency

Definitions

• This invention relates to apparatus and methods for dispensing and mixing liquids, and more particularly to such apparatus and methods that dispense and mix chemicals, and even more particularly to dispensing and mixing cleaning chemicals.
• Metering orifices have sometimes been used to achieve dilution ratios about 1 down to about 1000:1. More dilute mixtures are constrained by the volume rate of water available and by the smallest practical size of the metering orifices. Very small orifices are susceptible to clogging such as from contaminant particles or artifacts in the concentrated chemicals. In addition, the viscosity of the chemical imposes minimum size limitation of the orifice size.
• the liquid pressure introduced to an eductor based system is dependent upon the installation.
• Many variables can affect the water pressure to an eductor. Some of these variables can include but are not limited to the size of the plumbing supply piping ⁇ which causes pressure drops), and the placement of the eductor based system in the building. For example, systems installed on the top floor of a multi-leveled building may have less pressure than a similar system installed on a lower level of the same building.
• water usage can affect the pressure to the system. When the system is in operation and an additional device in the water line, such as a toilet, is used the additional water used by the toilet will reduce the water flow resulting in both the pressure to drop and less flow thru the system.
• an eductor creates a vacuum which draws in the chemical and mixes it with the water stream.
• the vacuum created is related to the fluid flowing through the edisctor.
• Chart 2 of FIG. 5 illustrates the vacuum created by a typical 4 GPM eductor at various flows.
• the maximum vacuum that can be produced is approximately 30 in- Hg.
• Eductors in general have a maximum vacuum level of about 27 in-Hg. This effectively caps concentrate flow and thus increases dilution ratios for high flows of diluent.
• FIG. 4 When pressure supplied to the eductor system varies the eductor (diluent) flow varies as shown in FIG. 4. Eductor vacuum is relative to flow.
• FIG. 5 shows results of vacuum varying with constant flow of chemicals having viscosity similar to that of water. Since the vacuum of the system will vary, the flow thru the metering orifice drawn by the vacuum will vary also. Referring to FIG. 3, the dilution ratios were computed with a vacuum of 25 in-Hg.
• Chart 3 of FIG. 6 shows the relationship of vacuum and constant concentrate flow through an orifice of a specific size.
• Dilution ratio is computed by dividing the fluid (diluent) flow through the eductor by the chemical flow thru metering orifice that is then mixed with the first fluid.
• Table 2 of FIG. 7 show the relationship of pressure to dilution ratio in a 4 GPM eductor combined with a metering orifice of .015" and with accompanying flow and vacuum parameters with constant concentrate flow.
• This table of FlG. 7 shows that pressure, fluid flow and vacuum and chemical through the metering orifice all increase up to flow of 4 GPM at which time the pressure and fluid flow continue could increase but the vacuum has reached its highest level and therefore flow of concentrates through the metering orifice reaches its maximum.
• FIG. 9 illustrates a pressure regulator set at 35 PSI and the flow out of the regulator and into the eductor thus is maintained at a constant flow rate, in. this case 4.0 GPM.
• the pressure regulator could have been set to a lower pressure and thus a lower flow rate provided through the eductor.
• Pressure regulators can be costly devices. Since they are mechanical and have moving parts they must be adjusted or replaced on a periodic basis which adds to both equipment and maintenance costs.
• a further object of the invention is to provide methods and apparatus for producing wider ranges of dilution ratios in a proportioner with fixed chemical metering orifices than hereto possible and with increased accuracy.
• a yet further objective of the invention is to provide am for producing accurate dilution ratios in fixed orifice proportioners despite variation in diluent flow and chemical viscosity and temperature.
• the invention contemplates structure and apparatus capable of producing a wide range of accurately diluted chemical mixes by cycling flow of the chemical through an eductor during diluent flow in response to a predetermined or commanded dilute ratio and in response to a variety of sensed parameters of fluid flow and viscosity.
• the result of this invention is the provision of a wide range of dilute ratios which are available through the use of a fixed orifice but are not so limited as, and are far more diverse than, a system which constantly draws chemical through that orifice.
• the results produced include ratios as rich as can be achieved through the given orifice at the highest of diluent flows and highest chemical viscosities and as lean as can be achieved through that orifice at the lowest diluent flows and lowest viscosities of the chemical used.
• the dilute ratios are not limited to mixes produced where the chemical is introduced to the diluent during the entire duration of diluent flow.
• Such apparatus and methods thus provides a wide range of ratios meeting the arbitrary regulations of health and other organizations and without the bother of multiple orifices, pressures regulators and the like.
• a user simply selects the dilution required and the viscosity of the chemical to be diluted (if the automatic temperature viscosity rate change selector to be described is not used). He then starts the water flow and the controller cycles a control valve in the chemical line to cycle chemical flow to an eductor based on the noted parameters and dilution ratio selected.
• the method thus contemplates the provision of a wide range of diluent-to-chemical mix ratios through cycling the chemical flow into the diluent.
• FIG. 1 is a perspective view of a concentrate dilution apparatus according to the invention
• FIG. 2 is a flow-chart illustrating operation of the invention
• FIGS. 3-10 are respective charts and tables referred to in the
• FIG. 3 is a first table illustrating dilution ratios for set parameters
• FIG. 4 is a first chart and illustrates pressure versus flow in a 4 GPM eductor
• FIG. 5 is a second chart and illustrates flow versus vacuum in a 4
• F IG. 6 is a third chart and illustrates typical vacuum versus flow through given orifice of 0.015";
• FIG. 7 is a second table and shows parameters of a 4 GPM eductor in combination with a given orifice of 0,015";
• FIG. S is a fourth chart and illustrates a graphical format of the information in FIG. 7;
• FIG. 9 is a fifth chart and illustrates parameters of pressure versus flow in a 4 GPM eductor with regulator.
• FIG. 10 is a third table showing temperature and viscosity parameters of typical dishwashing chemicals.
• FIG. 11 is a sixth chart and illustrates GPM eductor flow versus output pulses of a transducer as used in this invention
• FIG. 12 is a seventh chart and illustrates in graphical format the relationship of temperature and viscosity of a sample of liquid
• FIG. 13 is a fourth table illustrating parameters of cycling a valve to produce varying dilution rates according to the invention.
• FlG. 14 is a fifth table illustrating an alternative dilution producing operation according to the invention.
• FIG. 15 is an eighth chart and illustrates flow and vacuum parameters of an alternate 4 GPM eductor according to the invention.
• F ⁇ G. 16 is a diagram illustrating inputs to the control unit for the control valve of the invention.
• FIG. 1 there is illustrated details of one embodiment of the invention.
• a proportioner 10 includes a diluent (such as water) inlet 11 operatively coupled, through an on/off water control valve 12 and a transducer 13, to an eductor 14, coupled to receive and to discharge a mixture of diluent and chemical through discharge tube 1 into a mixed diluted chemical container 16.
• a diluent such as water
• eductor 14 coupled to receive and to discharge a mixture of diluent and chemical through discharge tube 1 into a mixed diluted chemical container 16.
• a chemical source or container 20 is coupled to or receives a chemical pickup tube or draw conduit 21.
• a chemical control valve 22 is operably disposed in conduit 21 between the chemical source 20 and a metering orifice
• Orifice 23 is operatively connected to pass chemical from conduit 21 into the eductor 14 at the venturi portion thereof.
• An electronic control 30 is operatively connected through line 31 to transducer 13 for receiving a signal from the transducer representing fluid flow.
• Control 30 is operatively coupled through lines 32, 33 to chemical control valve 22 for cycling that valve between open and closed positions to selectively open and close chemical conduit or pickup tube 21. On/off operation of valve 2 effectively cycles chemical flow into the eductor when diluent is flowing therethrough.
• a cabinet 40 covers the components comprising the valve 12, transducer 13, eductor 14 and portion of the discharge tube 15 as desired, with the on/off control valve being operationally accessible from outside the cabinet While not shown, the cabinet 40 maybe extended or compartmented to house control 30 and chemical control valve 22.
• the transducer 13 is preferably a flow transducer or flow sensor.
• a pressure transducer could be used, however, it would require more electronic circuitry as such transducer output typically comprises an analog signal.
• the output of a pressure transducer is generally not linearly proportioned to the flow in "GPM” (as used herein, "GMP” refers to ''gallons per minute”).
• GPM as used herein, "GMP” refers to ''gallons per minute”
• Eductor 14 may comprise any useful eductor, preferably capable of consistent operation at 1 GPM or at 4 GPM. Such eductor could be as described in the aforementioned patents.
• the control 30 preferably includes a plurality of components including a temperature sensor 36, a cycle duration controller 38, a dilution ratio selector 40, a viscosity selector 42, a temperature/viscosity rate change selector 44 and a microprocessor or programmable logic controller 46.
• a temperature sensor 36 preferably includes a thermocouple 36, a thermocouple 36, a thermocouple 36, a thermocouple 38, a thermometer, or a temperature/viscosity rate change selector 44 and a microprocessor or programmable logic controller 46.
• all these components could be mounted on a circuit board 48 or on other components or through other technologies for operatively mounting and/or coupling electronic components and chips, such as surface mount technology. Such technology itself does not comprise part of this invention.
• the temperature sensor 36 could be a board 48 mounted sensor. This type of sensor is economical and is produced by many manufacturers. One such sensor is manufactured by the Minco Company, headquartered in Minneapolis, Minnesota and marketed under the model name Minco S 102404, The temperature sensor should be capable of sensing temperatures from 40 degrees F to 120 degrees F. Typical applications would be a meat packing room in a grocery store that can operate as low as 40 degrees F or a restaurant kitchen which may reach temperatures of 120 degrees F. This sensor maybe mounted on the circuit board or may be removed from the circuit board to closer orientation with the chemical source and transmit the temperature signal via wire or with wireless technology. In this embodiment the circuit board 48 mount was selected for the low cost. Another embodiment would be the placement of the temperature sensor in the chemical container or in direct contact with the chemical in the fluid path. Such a location of the temperature sensor would add cost to the system. One such remote sensor is also made by the Minco Company under Model S56NA.
• the Temperature/Viscosity Rate Change Selector 44 is a variable device preferably mounted to the circuit board 48 and is used to input the change of viscosity of the chemical as it changes with temperature. As stated earlier the viscosity of some chemicals change with temperature. The viscosity change cause the chemical flow rate to change. Each chemical has a unique temperature to viscosity rate change. A typical rate change is shown in Chart 7 of F ⁇ G. 12.
• y is the viscosity
• x is the temperature
• "1070" is a constant.
• the value "-8" and "1070" are input to the microprocessor 46 by way of Rate change selector.
• This selector 44 may be mounted on the circuit board 48 as noted. In this embodiment the circuit board 48 mount was selected for the low cost.
• Such a temperature/viscosity rate change selector 44 can be of any suitable construction.
• One such selector is marketed by the Grayhill Company of LaGrange, Illinois under Model No. 76SB 1OT.
• the viscosity selector 42 is a variable device preferably mounted to the circuit board 48 and is used to input the viscosity of the chemical to be mixed. In this embodiment the selection is made via dip switches.
• the viscosity value to be selected could be from 1 to 3000.
• the viscosity selector 42 could also be a rheostat or other variable device. The dip switch was selected due to the low cost and ease of use.
• the temperature sensor 36, Temperature/Viscosity Rate Change Selector 44 and viscosity selector 42 could all be replaced with a single unit. Under this embodiment, the single unit could be remotely mounted and connected to the circuit board with wires or could transmit the data with wireless technology. One such single unit is made by Vectron Company of Hudson, New Hampshire under the Model Name ViSmart.
• the dilution ratio selector 40 is a variable device mounted to the circuit board 48 which is used to input the desired dilution ratio. That is the ratio of water to chemical. Any suitable and adjustable electronic input apparatus could be used. One such unit found useful is the selector made by Grayhill Company of LaGrange, Illinois as Model No. 76Bl OT.
• the cycle duration controller 38 is simply a selector for manually setting the duration of any dispensing cycle as desired, such as a timer.
• One such selector found useful is the selector made by Grayhill Company of LaGrange, Illinois as Model No. 94HBB16WT.
• All these components are preferably operatively connected to a microprocessor 56 or programmable logic controller, as desired, to control valve 22.
• the control valve 22 preferably comprises a quick open/quick close fluid valve, electronically actuated. In one embodiment it is a solenoid operated valve. Other types such as motor operated ball valves could be used in this application.
• the valve has a flow area of at least 0.030" in cross section to prevent clogging.
• the valve is normally closed and receives a signal from the microprocessor 46 to open.
• the duration of the open state is governed by input to the microprocessor 46 from the flow/pressure transducer 13, temperature sensor 36, temperature/viscosity rate change selector 44, viscosity selector 42, and dilution ratio selector 40 and cycle duration controller 38.
• Microprocessor 46 or compatible programmable logic controller can be any suitable microprocessor or controller.
• One such useful microprocessor is that made by Microchip Technology Incorporated of Chandler, Arizona under Model No. 12F683.
• pressurized water is supplied to the water inlet 1 1.
• pressurized water enters the flow transducer 13 portion of the apparatus and then flows into the eductor 14.
• Flow of water through eductor 14 creates a vacuum and draws chemical from the chemical container 20 through the chemical pick-up tubing 21 and control valve 22, into the flowing water diluent.
• This chemical/ diluent water mixture is discharged thru the mixed chemical discharge tube 15 into a suitable mixed and diluted chemical container 16.
• the transducer 13 transmits a signal proportional to the water flow.
• the rate of flow in gallons per minute (GPM) is linearly proportional to the output signal (pulses).
• Chart 6 of FIG. 11 shows the linear relationship between GPM and Pulses. This linear relationship may be different or different transducers used or flow passage configurations.
• the dilution ratio is the amount of water divided by the amount of chemical mixed and dispensed. The traditional way to achieve this was to change the size of the metering orifice in a typical system. According to the invention, however the improved method contemplates controlling the chemical to mix with the water at timed intervals.
• a mix ratio may be about 40: 1
• the dilution ratio for the same system would be 80: 1. Therefore by varying the open time for valve 22 to allow for the chemical to mix with the water the final dilution ratio of the water/chemical mixture can be infinitely varied.
• Table 4 of FlG. 13 shows how a valve 22 may be cycled to produce varying dilution ratios for a system flowing 4 GPM into a typical 4 gallon janitor's bucket.
• FIG. 13 illustrates that varying dilution ratios can be produced by varying how long the valve 22 is open. This system will work well for a given dispense volume, in this case 4 gallons. If one were to fill a 3 gallon bucket with the system set to 50:1 dilution ratio, the dispense time for 3 gallons would be 45 seconds. The chemical valve would be open for 48 seconds which would produce a dilution ratio of 40:1. [0072] If dispensing at water flow rates of less than 4 GPM, the above run times shown in Table 4 would not produce the desired ratios. The solution to this is to cycle the chemical control valve in even shorter increments. Table 5 of FIG. 14 shows the results of cycling the chemical control valve every 2 seconds or 30 times for a complete dispense cycle. With the system as described in FIG. 14 a dispense shorter than 60 seconds will give the same dilutions as a 60 second dispense.
• a control valve cycle of at least 4 times per minute is recommended to achieve accurate dilution ratios. Otherwise, a premature operator commanded water shutoff may adversely affect a desired ratio.
• the cycle duration control 38 changes the cycle time for the control valve. This is shown as a rheostat but dip switches or other means to vary the cycle time could be incorporated. This time is preferably adjustable from 1 second to 60 seconds.
• Such eductor achieves its upper vacuum very quickly at very low flow rates.
• the vacuum is relatively constant from low flow to high flow (the so-called “ramp-up" time being reduced as well as fluctuation of diluent pressure), thus giving uniform chemical flow through the valve at any reasonable flow rate.
• Performance is still not constant at very low flow rates where the vacuum has not reached it's maximum but this pressure is about 15 psi lower than almost all typical chemical dispensing installations, and front end performance up to 25 PSI does not adversely affect the operation practically.
• Such an eductor is not known to have been used in proportioning systems in the past.
• One such eductor useful in this regard is that manufactured by Hydro Systems Company of Cincinnati, Ohio under Part No. 440300.
• the operation of the invention requires electrical power. Many installations do not have available electric power or the installation of electrical equipment must be made by a licensed electrician. These requirements add substantially to the installation cost of the system and to the marketability of such a system. Batter power is the solution. Small, economical and easy to find batteries are preferred.
• the system preferably will operate on "AA" size batteries, PWM (pulse width modulation) technology, which is not new to electrical circuits can be used to activate the control valve thus substantially increasing the life of the battery.
• PWM pulse width modulation

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• Accessories For Mixers (AREA)

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• 2007
  • 2007-09-07 US US11/851,954 patent/US20090065065A1/en not_active Abandoned
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  • 2008-09-04 EP EP20080799145 patent/EP2188689B1/de not_active Not-in-force
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